A.C. Condition Behaviour in Amorphous WO3/CEO2 Thin Film

The a.c. conduction of amorphous thin film of WO3/CEO2 -AI in which aluminium is used as electrode, is studied in the frequency range 0.1 kHz to 104 kHz. The dielectric response of amorphous 58%WO3/42%CeO2 to the applied alternating field is believed to be Debye-like, where the polarisation could be caused by the transition of charge between W+6 and Ce+4 centres.lt is assumed that these centres are sufficiently close in this composition that appreciable interaction occurs, thereby causing the polarisation responsible for this type of conduction. Whereas the a.c. conduction in 81%WO3/19%CeO2, behaving as WS where s=1 around 10kHz, cou Id be interpreted in terms of Elliott model, that is two electrons are assumed to hop to gather from a D to D+ defect centres over a potential barrier separating them. At frequencies higher than
10kHz, the a.c. conductivity behaves as W2 in 81%W03/19%CeO2. This behaviour in this composition is very similar to that of chalcogenide glasses.